In a single-face corrugator of the type in which the corrugated paper is held by suction against the lower corrugated cylinder, the latter includes, outside its inner chamber filled with saturated heating vapor, separate longitudinal channels in the peripheral body of the cylinder. Each channel is connected to the exterior via axial channels and elongate grooves machined in the periphery of the cylinder, and can be connected to a suction apparatus via two hollow and sealed circular arcuate sectors bearing on the part of the face of the cylinder associated with the holding region on the latter. The grooves are staggered and machined in circumferential portions of the periphery of the cylinder so as to extend over several corrugations thereof. An additional blowing sector permits detachment of the corrugated paper.